import java.util.Scanner;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: WHY
 * Date: 2022-07-15
 * Time: 23:53
 */
public class Test1 {
    public static String func(String str) {
        int []array=new int[255];
        StringBuilder   stringbuilder=new StringBuilder();
        for(int i=0;i<str.length();i++){
            char ch=str.charAt(i);
            if(array[ch]==0){
                stringbuilder.append(ch);
                array[ch]=1;
            }
        }
        return stringbuilder.toString();
    }




    public static void main(String[] args) {
        Scanner  scanner=new Scanner(System.in);
        while(scanner.hasNextLine()){
            String str= scanner.nextLine();
           String ret= func(str);
            System.out.println(ret);
        }

    }
}
